I have "bummed" rides on private planes when my own was down for maintenance away from home base. I hang out at the FBO and check who is going where and most times I got within driving distance. Coolest flight was a Citation deadheading to our home base. Got 1.5 hours in my log book since the Pilot in Command was a Certified Flight Instructor.

That said, I seriously doubt anyone with a airplane will volunteer to take someone multiple times for free. And if they accept expenses, the pilot better have a Commecial pilot certificate and some pretty good insurance.

Cheers